Phase l clinical trials frequently involve 18-26 year-old individuals. Subjects are monitored frequently for the occurrence of soft tissue lesions (e.g. aphthous lesions), tooth staining and other manifestations in the oral cavity. However, there is a paucity of data about these occurrences in a "normal" population, i.e. without any treatment or intervention. Fifty otherwise healthy 18-26 year-old students at Georgetown University are examined six times over the period of one year. At each examination a)any soft tissue lesions are noted and photographed; b)teeth are photographed; and c)a bleeding index determined. At the completion of the study data will reflect changes in these parameters.